Thanks for your response. It was worth a shot!
The rule has had an effect - It has changed the hostnames to all caps, however has not merged all the services together.
In the example the LIVERESOURCES (2 services), liveresources (4 services) and LiveResources (78 services) have become only LIVERESOURCES with 2 services.
I have looked at another monitoring system (datadog) which correctly merges the Resource Groups with different case names together. I wish CheckMK would 